Air space insulated electric cable



Oct. 1, 1940. 4 o. coRDz-s Er AL. 2,216,386

AIR SPACE INSULATED ELECTRIC CABLE Filed July 6, 1938 Patented Oct. 1, 1940 UNITED STATES PATENT OFFICE Otto Cords, Berlin- Sudende, and Gerhard Nehmiz, Berlin-Grunewald, Germany Application July 6, 1938, Serial No. 217,794 In Germany July 13, 1937 4 Claims.

This invention relates to an airspace insulating electric cable of the type disclosed in the prior application, Serial Number 175,936, led November 22, 1937.

5 The object of the present invention is to provide an air space insulated electric cable, and more particularly a high-frequency cable wherein the support for the central conductor is constitutedby at least one tape wound helically about the central conductor in spacial disposal thereto, a thread or threads wound about the said tape and between the convolutions thereof and about the central conductor with a pitch smaller than that of the helically wound tape for the purpose of supporting the central conductor with respect to the helicaliy wound tape, and at least one further tape superimposed on the said rst tape and rmly secured thereto for the purpose of securing the position of the supporting thread or threads.

'I'he invention is illustrated by way of example in the accompanying drawing, in which:

Fig. 1" is a perspective view illustrating a supporting system according to the invention.

Fig. 2 is across-section showing on enlarged scalela piece of the tape system according to Fig.

Fig. 3 is a modication of Fig. 2, while Fig. 4 showsl an additional embodiment for 3o connecting the layers and securing the thread.

` In the drawing I is the central conductor of the cable, about which there is disposed in special relation thereto a helically wound tape system. In the embodiment shown this tape comprises two superimposed layers 1 and 8. These layers are connected together, for example, by means of anv adhesive and may for example, bemade of non- I metallicr material. When the winding is being produced on the machine the supporting thread 4 40 is wound in such a manner that it is located between the layers 1 and 8 and consequently is securely held in position thereby. f

The tape winding, however, is not limited to two layers, and as shown in Fig. 3 there may be 5 provided, for example, three layers 1, 8 and 9. In

this figure the thread 4 is shown as being located between the layers 1 and 8, but naturally it might also be provided between the layers 1 and 9.

In the embodiment according to Figure 4 the two layers 1 and', which may consist of paper, 5 are furnished on their oppositely disposed faces with a coating l0 of synthetic resin. As before the thread l is disposed between the two layers 1 and 8, and upon the application of heat the syn thetic resin ill is caused to melt, and after harden- 10 ing it unites the two layers 1 and 8 and thus iirmly secures the thread 4.

Il' desired, the synthetic resin 'can also be hardened.v

We claim: 1I

1. An air space insulated electric cable, and more particularly a high-frequency cable, comprsng a central conductor, a support'for the said conductor including at least one tape wound helically about the. central conductor in spacial 20 disposal thereto, a thread wound about the said tape and between the convolutionsthereoi' and about the central conductor for supportingthe central conductor with respect to the helically wound tape, and at least one further tape super- 25 imposed on the said rst tape and rmly secured thereto for securing the position of the supporting thread. Y

2. An air space insulated electric cable according to claim 1 in which the helically wound and $0 superimposed tapes consist of paper and are connected together by an adhesive.

Iapplication ot heat and unites thetapes when subsequently hardening.

4. An air space insulated electric cable accord- 40 ing tociaim 1 in which the helically woundy and superimposed tapes are connected together by a synthetic resin.

vo'r'ro coRDs.

GERHARD Nmnz. 

